White-Nose Syndrome (WNS), caused by a fungus, has devastated bat populations in the eastern United States since it first appeared here almost ten years ago. An estimated 5.7 million bats have died, and conservationists have scrambled to find solutions.

The bats released last week all had White-Nose Syndrome, and were successfully treated with a common bacterium that releases Volatile Organic Compounds (VOC) with anti-fungal properties.

This hopeful story may be an important first step in managing WNS. And its scientific backstory is just as fascinating.

This innovative treatment’s development began not with bats, but with bananas.

That’s right: the bananas on your supermarket shelf play a surprising supporting role in bat conservation.

Research on delayed fruit ripening led to a surprising revelation. Photo: Steve Hopson, stevehopson.com

Researchers and graduate students began noticing another effect of these VOCs: fungus inhibition. The fruits exposed to the bacterium were not getting moldy.

Chris Cornelison was at the time a graduate student at Georgia State. He had been seeing the photos of dead bats piling up in caves, and a thought crossed his mind.

“I was standing there looking at a bucket of moldy bananas next to a bucket of bananas with no mold,” says Cornelison. “If the bacterium could be so effective on fungi on bananas, could it have similar effects on fungus on bats? It was one of those leaps of thought in science that maybe only a grad student could make.”

Cornelison, now a post-doctoral research associate at Georgia State, exposed petri dishes of the fungus that causes WNS (Pseudogymnoascus destructans) to the bacterium.

“The first exposure seemed too good to be true,” says Cornelison. “I had to test it five more times before I believed the results. It had dramatic effects on the fungus. It seemed like this could be a big step in managing white-nose syndrome.”

A Cooler Full of Bats

Other bat researchers and conservationists saw the potential for this bacterium and the potential to take action against a conservation issue that was frustratingly difficult to combat.

“When white-nose syndrome was first documented, we were scrambling to find information,” says Katie Gillies, director of the imperiled species program at Bat Conservation International (BCI). “We had to research the disease, understand how it works, how it spreads. But we also knew we had to take action.”

“In 2012, we tried our first crazy idea to build an artificial bat cave that could help us provide a hibernating place for bats that we could clean every year,” says Gina Hancock, state director for The Nature Conservancy in Tennessee. “Then when we formed a partnership with BCI, we kicked around what was the most promising work being done, and biocontrols came to the top of the list.”

Hancock notes that there was no public money being spent on this kind of research, so The Nature Conservancy and BCI sought proposals to accelerate the research.

At Georgia State, the laboratory results continued to be impressive. The next step was to test the bacterium on bats in a laboratory setting, and it worked. Bats suffering from WNS recovered.

Of course, the bacterium is essentially a biocontrol – a biological method of controlling an invasive species. As Cornelison notes, the use of biocontrol has a checkered history, one filled with unintended consequences.

The impacts of the bacterium on other native organisms would have to be fully vetted. But in the meantime, bats could be treated in a limited field setting.

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First, bats suffering from various levels of WNS were collected in the wild. They are not actually treated with the bacterium; it’s the VOCs that have the anti-fungal properties.

The bats were placed in a mesh bags, then put in a large Yeti cooler containing plates of the bacterium. They stay there for 24 to 48 hours.

The treated bats were then placed in an enclosure in a wild cave, where they spent their hibernation. This spring, they were collected and tested for presence of WNS.

“We tested for their fungal load and compared that to the fungal load when we first captured them,” says plant pathologist Daniel Lindner, of the U.S. Forest Service’s Center for Forest Mycology Research. “The bats had no detectable signs of white-nose syndrome and could be released.”

Some of the bats had such severe wing damage from the fungus that they could not be released (these animals will serve as conservation ambassadors), but 75 were released at the Mark Twain Cave Complex in Hannibal, Missouri.

The bacterium does not cure WNS; it arrests the development of the fungus and inhibits its growth. But it is still a tremendous first step in finding ways to manage the disease.

From Lab to Cave

Could this bacterium be used to treat caves? Yes, but first more tests are needed. The treatment has to be tested for potential toxicity to other cave organisms, including native fungi. (This is why fungicides have not been used to fight WNS; they typically kill all fungi, not just the harmful species).

“We have to make sure it’s not going to upset the cave’s delicate ecology,” says Lindner.

Once those tests are completed, how do conservationists actually treat a wild cave? Researchers are considered a nebulizer that pumps the VOCs into the cave. “It’s a very sophisticated version of a commercial grade air freshener, like what a hotel might use,” says Lindner.

It could lead to treatment of caves, mines and bunkers – potentially creating safe havens for bats. “In this trial, we had to touch every single bat,” says Gillies. “The goal is to optimize this tool so that we can treat a large number of bats without touching them.”

“This is one tool but we will need many more to manage this disease,” says Lindner. “But tools like this could help us manage the disease. It buys time for bats to adapt to the disease and develop resistance. That could prevent extinctions and allow healthy bat populations to rebound.”

For several years, talking to bat conservationists was an exercise in despair, in helplessness. WNS is still a major problem, and one that will continue to require innovation and research on a number of fronts.

But the sight of bats – bats that would have died of the disease – flying through the woods after successful treatment suggests a new chapter in this story. A new hope. “We are finally at the point where we can intervene on white-nose syndrome,” says Gillies. “It is not a silver bullet. We need more tools. But it is a first step. A huge first step.”

Matthew L. Miller is director of science communications for The Nature Conservancy and editor of the Cool Green Science blog. A lifelong naturalist and outdoor enthusiast, he has covered stories on science and nature around the globe. Matt has worked for the Conservancy for the past 14 years, previously serving as director of communications for the Idaho program.
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Great news.
I have suggestion for nebulizers. Omron makes hand-held, 4xAAA battery operated ultrasonic nebulizers which produce an aerosol without contamination or heat. We modified one of the small handheld ones to produce an aerosol of 1um PS microspheres that worked as a test material for smoke detectors in clean rooms.
There are also larger ones that may have a higher capacity and could run for longer for saturating a cave or other location.
The only question is if the ultrasonics would bother the bats.

Ellen,
Thank you for the suggestion. The ultrasonic nebulizer you mention (Omron MicroAir) is one of the nebulizers I initially tested before choosing to develop my treatment platform with the jet-type nebulizer (Pari TrekS). Although ultrasonic nebulizers are favorable over jet nebulizers in a few areas, there were a number of factors that led to the decision to choose to develop with the jet-type.
Kyle Gabriel

Wonderful news, but also ironic. The grad student’s discovery is reminiscent of Alexander Fleming’s discovery of penicillin, only the reverse: Fleming’s had mold dining on bacteria. Do we now see mold’s deserved comeuppance? Payback time for bacteria?

[…] Last week an announcement was made that a group of bats were successfully treated for White-Nose Syndrome (WNS) and released at the Mark Twain Cave Complex in Hannibal, Missouri. This a momentous occasion in the world of conservation where good news can be rare. My post is based on the blog post from The Nature Conservancy’s Cool Green Science Blog, “Bananas toBats: The Science Behind the First Bats Successfully Treated for White-Nose Syndrome” https://blog.nature.org/science/2015/05/27/bananas-to-bats-the-science-behind-the-first-bats-successf&#8230; […]

The chemist in me is asking a basic question. “VOC” is a very broad label. Is anything known about the molecular identity of this particular set of VOCs? Knowing the identity allows the prediction of potential unwanted effects.

Once the bats are released they will be subject to re-infection if they go back to an infected cave so this is indeed a bandaid on a cancer. It is great news but if there were a way to treat the bats and then keep them quarantined until a safe haven can be established for them wouldn’t that better? It is a very circular problem is it not? The issue of the Voc killing off other good fungi is like our problem with antibiotics and the biota in our guts. However we have developed ways to counteract these effects to some degree. We might have to preserve populations of the good fungi to reintroduce them after the “sick” caves are disinfected so to speak. What think you?

Speaking of compounds to nebulize: Has anyone tried Grapefruit Seed Extract (GSE), produced by Nutribiotic and other companies. It is fungicidal, bactericidal and viricidal at low concentrations, and is an organic product.

Hi Carolyn,
I will let the researchers comment on the use of GSE in controlling white-nose syndrome. However, I will note that I have seen it used in wader cleaning stations along trout streams to stop the spread of invasive species like New Zealand mud snails, and it appears to be effective.

This may be way off, but I treated my thrush (a yeast/fungus) with acidophilus tablets. Is there a possibility of providing the bats with a food or water source treated with acidophilus, until the fungus no longer has a source. I was able to ween off of it eventually. I just wondered if this route of treatment, as the other lady said, is more natural and perhaps more sustainable. Certainly, it would cause less impact on surrounding ecosystems.

Love your observations and successful use of the fungi to help the WNS of our bat population. I had bats stop at the under hanging of our home in White Lake MI.The neighbor and I encouraged them to roost their. At first I thought they were hummingbirds. About same size and fast flight patterns.The neighbor liked our bats so much he put up a bat house. We need people like you to continue with your work.

One person mentioned the possible re-infection. But with the bats that had WNS, they survived with the help of the VOC’s, and are healthy now, might they have gotten a vaccine-like effect, and be immune to re-infection?

Is there any research in seeing if these VOC’s could be used against black mold in homes. Thousands of houses are torn down because black mold is so aggressive. Someday, may we see homes pumped full of VOC’s becoming mold-free?

Is there any chance that the bats could eat the VOC’s and like plants that absorb pesticides, they would be protected?

Can small fungi-seeded “packets” be sold alongside bat houses? Wet, and attach inside the bat house? We have bat houses outside our own home and the ability to stop WNS in bats using those as roosts would be wonderful!
Dried-out rubbery, impregnated agar in a mesh suet-type bag would be easy to soak in water for a few hours, then tack inside the bottom of a bat house.

If the VOCs are found to be fairly targeted on the white nose fungus, then natural biological vectors for bringing it to the bats, or bio-engineering bat fur bacteria to produce these VOCs might be considered.

Testing the spectrum of fungal toxicity: is anyone checking bat caves in the vicinity of banana plantations, to see if the bacterium or related sp. with similar VOC emissions are present? Just a thought.

Constantly spraying all bat caves is unrealistic and spraying selected ones is a limited short-term solution.

I have a sneaking suspicion that all the ‘bio engineering’ that groups like Monsanto are doing are the reason this occurred in the first place. Perhaps less interfering in this way would go further. The paranoia in me is saying that first they have attacked our bees and created ‘new and improved’ bees, and now they are attacking our bats. Anything to gain complete control of the agriculture of the world.

Many comments made by readers brought up good points that the researchers may not have been aware of.
Sharing our thoughts and comments, just like the observations that Georgia State student Chris Cornelison made and decided to test his thoughts to see if there was any change.
Sharing and communication resolve many things.

The Bats thank you….and I do too!!!!! Keep up the good work, bats play a very important role in our eco-system.

We are nowhere near any sort of method for eradicating WNS in the wild.

“Saving” bats that would not survive on their own, and releasing them where they can mate with true survivors does damage to the only likely long term hope for these species to eventually re-fill their ecological niche. The hope is that natural survivors have some behavioral or genetic advantage that allowed them to survive and that they can pass down to future generations. Keeping non-survivors in the gene pool is a really good way to sabotage adaptation to the reality that WNS is probably here to stay.

Saving individual bats that would have died is great, but sadly they no longer have a place in the wild. The organizations saving those bats should be responsible for finding life time housing for them out of the wild.

[…] To learn more and see a map of its spread across North America visit Bat Conservation International’s Introduction to White-nose Syndrome and the Organization for Bat Conservation’s page on White-Nose Syndrome. As doom and gloom as WNS has been, we now have a glimmer of hope. Seventy-five bats were recently treated for WNS and successfully released in Missouri. Read more about these bats in the Nature Conservatory’s blog post, Bananas to Bats: The Science Behind the First Bats Successfully Treated for White-Nose Syndrome. […]

Great news, but why the caution? ALL THE BATS ARE DYING, there is nothing to lose if you treat the bunkers and mines with any fungicide, no delicate ecosystem to balance, caves, Ok, whatever. I’m frustrated with the slow pace and an overabundance of caution. It’s like taking your time saving an infant from a burning car because you don’t want to traumatize it. Ecologists drive me nuts sometimes

Bravo on this breakthrough! My wife and I live near Trenton, NJ and my house had a several bats living in our roof. They disappeared about five years ago and we have not seen a bat flying in our backyard since. Their absence has let the mosquitoes take over to a point that it is uncomfortable to be in our backyard on warm summer nights anymore. You get eaten up by the mosquitoes very quickly there. Hopefully with this breakthrough New Jersey will be enjoying the return of our nighttime flying friends very soon. We can hardly wait!

Awesome. Observation and questions at a moment in time with the confidence to think one can make a difference is a powerful combination. Follow-through and determination seal the deal. Bananas. Nature. Delicious and mysteriously wonderful.

Congratulations everyone……… ! Staving off this terrifying scenario is massive. My Hats off to you all… My God crack the seal on a bottle and celebrate. ! These little animals are an integral part of the ecosystem and it is crucial to hold on the numbers still left and maintain these numbers as research continues on a more permanent cure.

Such good news-thank you Geogia State University and Chris Cornelison! Hundreds of thousands, perhaps millions of bats, will be saved by your work. Thank you, thank you. Bats are marvelous creatures. I hope to put bat houses in the large ( almost an acre) yard of the house I bought and hope to be in soon!!!

[…] and the bats roost extremely close to each other. If you want some good news about WNS go to this website. If you want some other places that WNS has been or is going, go to this website . If you want […]

Wow! Great!
I came across this article while looking for woods with certain tannins in hopes to build bat boxes that contain some ani-fungal agents to help them at least rest in a safe place and I don’t know if they over winter inside the bat boxes or not, but if so then a safe place to over winter.
Do you think Bat boxes could be built to contain these VOC’s in hopes that they will prevent at least the fungus from thriving where they sleep in a controlled way?
Please reply if you can, I would try to produce bat boxes that could do that if it were viable. I am from The Laurentians north of Montreal, where we always took great pleasure in watching the bats at night, come out like our personal hero’s to deplete the mosquito population. In recent years we haven’t seen a single bat all summer.

I’ve had Little Brown Bats every year since 2008 in my bat house in the Blue Ridge Mountains, Virginia–except 2014 & 2015, when they did not return. I was afraid they’d died of the white nose syndrome. But this past summer of 2016 they were back! Not as many, but I’m so happy to see them again.

Spectacular news! Congratulations to each and all the bright, inquisitive, determined minds involved, especially that extrapolating grad student! Particularly admirable is the deliberate caution being exercised to avoid collateral damage; the lessons of history were not lost on this team! A tip of the hat to Georgia State!

YYYAAAAAAYYYY! You people are AWESOME! Thank you for helping bats, one of our most un-appreciated yet VERY important mammals. I shudder to think of the load of insects we’d all be fighting and suffering from if it weren’t for our microchipterian, mosquito slurping little buddies.

Keep up the research. Try to inform the public of the importance of bats…..( They eat massive amounts of mosquitos ) Which could lead to fewer cases of human diseases…ie Encephalitis…….Rabies and the like!! If people thought it would help them, They might be willing to donate Funds!!!

Fascinating and wonderfully positive news. We have a few bats flitting about near where I live in upstate NY and I’m always wondering if they are o.k., or going to get white nose syndrome. This is an encouraging lesson in the power of observation and creativity. Yes please, go cautiously with this treatment…I love that scientists are paying attention to the whole ecology of the bat caves. Good news here tho’. How are the bananas? (could this VOC concept work on bees?)

We have a large population of Bats in a cave near the Guntersville, Al. dam. The number of bats have decreased greatly over the last 2 years because of the fungus. I have always wonder why you couldn’t spray them with something when they fly out in the afternoons? The opening of the cave is like a small half moon because of the level of the Tennessee River. Doesn’t the fungus start in the layers upon layers of feces in the floor of the cave?

This is wonderful, promising news! While caution is always the best policy, it’s thrilling to possibly see light at the end of a sad tunnel for bat populations. Here’s to good things for our struggling planet’s ecology!

This is wonderful news. When I moved to the Northern Adirondacks in 1982, we had hundred of bats flying over our river at su set catching bugs on the wing. By 2005, there were no more bats on the evening. I have not seen a bat in the last 4 years. I live alone on 24 acres of wooded land with a trout stream at my front door. Plenty of room for bats to thrive. Do you think they all disappeareddue to WNS???

Has anyone thought to dust the bats on their egress from the caves with nystatin powder. with the possibility that they would not carry enough back to their caves in the morning to affect the resident beneficial fungi.

Do we know where or how this fungus originated in the first place? It doesn’t do any good to get rid of the symptoms, if the source is still out there. What changed in the ecosystem to cause this eruption? Was there a chemical imbalance in caves, or in something that they were feeding on that caused them to bring the fungus back to the caves?

When I was about 10-12 years old I spent a few years in an upstate boarding school. The school marm kept a bat in a large jar and I became fascinated with the wonderful creature. Though many people find bats to be repulsive I think that they are wonderful. They are one of nature’s magnificent creations and fill an extremely important niche in it’s hierarchy. Although most people are afraid of bats, the flying mammals are generally harmless to humans and actually perform a variety of useful services. Insects are a favorite midnight snack among the bat crowd. Blood-sucking mosquitoes and pests that can harm crops are toast before a hungry bat. Because of that, bats save farmers from having to spend millions of dollars on pesticides. Thank you so much for sharing this article.

I live in Western NY on Chautauqua Lake. Every summer I enjoyed watching hundreds of bats fly around at dusk. I never had to worry about mosquitos. Last year and this summer I didn’t see one bat. Chautauqua Institution, a world famous summer cultural center, was famous for its bat population. Wherever you turned a visitor would see a bat house. Sadly they weren’t used in recent years. If researchers want to release experimental bats in our area, we would be very pleased.

A Facebook comment was made that this method for treating WNS has been neither publisher nor peer reviewed. It also suggested that reporting such until-reviewed science was irresponsible.
Is it true the science hasn’t been peer reviewed and published, and if yes, could you please talk about what you see as the ethical considerations about reporting on this type of research?

Drs. Amelon and Hooper from the University of Missouri deserve accolades for their unending part in this research endeavor. Sybil and Sarah were the instigators and bat lovers who worked with Chris to carry out the research mentioned in the article. Sybil doesn’t want another bat to die, and neither do I!

If you get the funding, can you alter the VOCs to only attack that particular fungus? Like they are doing to viruses to attack others? That way you wouldn’t have to worry about the other fungi in the caves.

Bats are so critical to our eco-system, but VOC bio-controls are seriously dangerous to our environment and not the toxic bandaid we want to use on bats or anything else, especially our bananas.

This article tricks us into thinking bananas cured bats of White-Nose Syndrome. But reading it details that this bio-control is a VOC chemical that will kill ALL fungi in our caves that are dependent upon a very delicate balance, and don’t actually cure the bats either.

The problem with bats is CLIMATE CHANGE. Our warming climate breeds the white fungi that grows on the bat’s noses and bodies. The problem with climate change is our dependence on fossil fuels and our destruction of our planet. Turning THAT around is what will help our bats.

Let’s hope that the weather people are right about a colder winter this year. That will do the most to help the bats and it won’t kill all our beneficial fungi starting another eco-imbalanced, catastrophic crisis. If we have a colder winter and the bats recover this year that bio-controls were used, where do you think the credit will go? Think the bio-control engineers will claim success?

If you think we have problems with our liberal, black, Democratic president, just THINK of what it will be like under Trump. I’m going out to help Hillary Clinton get in. It’s the best thing I can do for our environment.

I first learned of WNS from reading Elizabeth Kolbert’s wonderful book, THE SIXTH EXTINCTION. I’m heartened to learn that, perhaps, something can be done to prevent the extinction of theses bats. They are so vital to our environment.

I’m not a scientist, but could some set up be created to detect bats exiting a cave, and then nebulize them as they exit? A motion detector or timer that is set to the times they typically leave the cave in the evening to forage for bugs. And even when they return. This could save the cave environment, and yet inoculate virtually all that enter and exit. Parents would rub it onto the young inside.

This news has made my day, as I live in Shaftsbury, VT next to Lake Shaftsbury. Years ago I put up 5 bat house as we had terrible mosquitoes and other biting insects. The bats did a grand job on cutting down insect population. Then cam the White Nose Syndrome and all my beautiful bats wee gone. This past summer I saw 4. Let us hope that the cure has finally been found, and we so need our little friends to pollinate and protect us from biting insects.
Please keep us updated on test results.
Thank you for all you are doing.

How great it is to read something positive about the fight against WNS. I am from Atlanta and am so proud that Ga State (my daughters’ and son- in-law’s alma mater) is so actively involved in a solution to this problem. Keep up the good work!

When I was 8 years old a neighbor came over and asked my friend and I for a favor. “Some creatures are making a mess on my car in the garage. Please come over and help me. I will give you each a tennis racquet. I am going to shoot water into the roof and if anything comes out, hit it, kill it.”
Totally ignorant, as was the lady, we swatted bats as they fluttered about in confusion. As I remember, we killed about six or eight including the injured one which I picked up and of course, was bitten by.
Now, 76 years later, in another state, we have two big bat houses mounted on the front of the garage and a third atop a 16 foot pole in the yard. The bat houses have been in place for seven and ten years and to date we’ve had three bats. Hoping for more in the spring. I guess ignorance is not a sin but I still feel terrible about that experience

It was exciting to learn about the science, scientists and hope for bats. It seems that we have so much to learn about the interrelationships in nature. Perhaps, at one time this species of bacteria occurred naturally in caves. At any rate, I love your writing style. And, I need to renew my Nature Conservancy membership. The letter is in my mail basket.
Thank you.

This is an answer to my prayers! What wonderful news!!!! I pray that this Syndrome can eventually eradicated and/or the Bats develop the resistance en masse to eliminate it as a threat. Thank you for publishing this!! <3